Furnace



P. L. PFANENS'CHMIDT. I

FURNACE.

APPLICATION- FILED JAN-Z, 1915 1,413,932. Patented.v Apr. 25, 1922.

Pied.

P. L. PFANENSCHMIDT. FURNACE APPLICATION FILED JAN 2,-l9l5- 1,413,932. v Patented Apr. 25, 1922.

3 SHEETS SHEET 2. v

WITNESSES: IV Y V'Ta/E;

P. L. PFANENSCHMIDT.

FURNACE.

APPLlCATlON FILED JAN-2,1915.

Patented A 25,1922. SHEE:|' 3.

LETS

UNITED. STATES PATENT OFFICE.

FURNACE.

Application filed January 2, 1915. Serial (GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41

To all whom it may concern:

Be it known that I, PAUL LUDWIG PFAN- ENSCHMIDT, a subject of the German Emperor, residing at Westfield Terrace, Thornhill Lees, Dewsbury, in the county of York, England, have invented certain new and useful Improvements in and Relating to Furnaces, of which the following is a specification.

This invention relates to the production of articles made from quartz or silica sand or crystal and means for such production whereby I am enabled to produce artlcles in size and thickness greater than hitherto.

used quartz or silica ware has been previously manufactured on a commercial basis for some few years, such ware has however not satisfied all the requirements of the interested industries as it has in many cases been too small in size andthickness, and costly to produce, the number of shapes product-able without great waste being-limited.

The present general method of manufacture is to melt pure quartz-sand or crystal round a single graphite electrode, and then to transfer the hollow mass of molten material so obtained into a metal. mould or form and blow it into the desired shape by means of compressed air or by gases generated by a gasifying body such as wet wood, wet paper, or potato placed in the centre of the molten material.

This method is wasteful as it necessitates the formation of a closed cylinder or bottle like object in every case, irrespective of the finished shape of the article it is desired to produce, and the surplus material which has to be removed very often forms a large proportion of the total amount of melted material.

The use of one electrode or resistance and the formation of a cylinder orthe like by means of expansion through airor gas must of necessity limit the size, thickness and shapes of the articles which may be produced, although in some instances it has been proposed to use several electrodes, but means and apparatus have not been described for the eflicient arrangement and operation of same such as the rapid with- Specification of Letters Patent.

Patented Apr. 25, 1922. No. 215.

STAT. L, 1313.)

drawal of the resistances in order to ensure the rapid handling of the material such as are hereinafter described.

As before stated according to my invention I aim to produce silica ware which is not only capable of being made to a thickness greater than hitherto, but which is also capable of being made in larger sizes than hitherto.

To carry my invention into effect I propose to employ more than one electrode or resistance of any suitable shape, such as round, flat, oblong or otherwise suitably formed, and such electrodes may be connected either in parallel, series or a combination of both, but by preference in series.

he sand to be melted maybe placed either round the resistances above or below, horizontally or vertically, so that on the application of current, heat is generated and the molten envelope of the quartz sand or crystal is formed around the resistance. The resistances are so disposed in relation to one another that any sand which may be between them is melted and so that the heat is utilized.

n the completion of the operation of melting, the resistances are withdrawn and the envelope is compressed, so that one solid sheet is formed. It will be noted that no air or gas is required.

he pro'ductionof a solid sheet and the employment and disposition of a plurality of readily removable resistances and the utilization of the necessary current enables me to produce ware of considerable size and of a thickness not heretofore obtained.

Instead of forming articles to the required shape by means of compressed air and gas as hereinbefore mentioned, said articles are formedby mechanical pressure, such as is obtained by a press or rolling mill.

Themould will be provided with suitable apertures for the escape of the surplus material and may also be provided with a cutting edge or edges adapted for the removal of such material.

In the accompanying drawings I show a form of furnace adapted to carry out my invention and to form thick sheets of the material in which Fig. 1 represents an end elevation partly in section. a

Fig. 2 represents a plan.

Fig. 3 represents a side elevation partly in section, with the furnace turned over.

Fig. 4 represents an elevation of the other side with the furnace in the normal position.

The furnace consists of a cast steel plate with the two ends turned up to form two sides with the lid A hinged longitudinally in the centre by hinges marked a, so that each half of the lid can be separately lifted, the whole being completed in box form by the side designated B hinged to one of the bottom edges of the plate and by the door to the side indicated by C which opens by sliding same on the trolley b along a pair of rails c.

The two turned up ends of the plate are lined with graphite blocks J screwed to the ends. Graphite blocks d are laid side by side and clamped with iron bands (Z to form two sheets, one of which is used to line the bottom, the other (divided longitudinally) to linethe lid. The longitudinal division is made in order to allow free movement to the hinges a.

At 6 spindles with flat square heads held in position by the iron bands are let into the graphite blocks 65'.

These spindles are inserted into screw wheels f in order that the space between the carbon blocks d may be increased or decreased so as to enable quartz sheets of varying thicknesses to be produced. The screw wheels are held in place by means of bushings fastened to the lid and bottom of the box.

Into the castings of the side B six apertures and into the door or side C seven apertures are left, into each of which graphite blocks or electrodes g and g are fitted. Each graphite block g and g is surrounded by an insulator h the whole resting on brackets 2' cast on the side B and the door C as shown. c

The graphite blocks 9 and .g are split horizontally into equal halves, holes being bored through at the split for the rece%tion of the graphite resistances k.

ach of the graphite blocks g carries one end of two resistances and the graphite blocks g carry one end of one resistance (see Fig. 2), thatis two resistances k are mounted at one end in the blocks 9, while one resistance is mounted at one end in each of the blocks 9'.

All the graphite blocks 9 and 9' and the insulators and electrodes are clamped together by the bars Z the bars being screwed down by the screws m and the electrodes individually tightened by the set screws n.

By loosening the two handles m in the side B it is possible to withdraw all the electrodes together by moving the door C along the rails c.

The current is connected in series and brought to the furnace b the copper conductors o and 0'. ach conductor is connected by clamps to one of the graphite blocks g these two gra hite blocks being made somewhat longer t an the graphite blocks 9. v

The furnace is pivoted on two trolley stands D made to run on rails.

The furnace described is capable of pro ducing quartz sheets up to 4'0 x 2'6" of a thickness varying up to 5" and is not intended as a mould for shaped articles.

By making a larger furnace and rearranging the resistances in a vertical position, sheets or blocks of a thickness greater than 5" can be produced, and for the obtaining of very thick sheets we may employ rows of resistances one above the other suitably spaced, the current being arranged both in series and parallel.

In order to work the furnace it is put into a horizontal position and the side B and the door C are tightly screwed to the box by means of eye bolts.

The resistances k are then fixed in the graphite blocks g and g surrounded by the insulators h and the whole is secured by the tightening of the bars I by means of the screws m and the set screws n.

The space required in the box in order to make quartz sheets of the thickness desired is then adjusted by the screw wheels f and the box is filled with sand.

The lid a is screwed down with eye bolts and the furnace is then turned into the vertical position and the conductors 0 and 0' are plugged into connection with the current and the current is switched on.

When the process of melting is completed the current is switched off, the conductors o and 0 are disconnected and the furnace is wheeled in front of a press or rolling mill and turned into a horizontal position. I

The resistance is in the side B are loosened in the graphite blocks g by slackening the screws m, the eyebolts on the door C are knocked off and the resistances are withdrawn by moving the door C along the rail 0.

The side B is then dropped down, the half of the lid A nearest the side B is lifted, and the quartz sheet is drawn out of the furnace box and across the bottom half of a suitable matrice in a press or rolling mill, when the top half of the matrice is either pressed upon or rolled over the quartz sheet.

The matrices are made in one or moresections and are heated or cooled as may be required and are held together by a movable frame provided with screws to hold the sections together.

Any surplus material forced out of the matrices is cut away by cutting edges, and the article is then removed'from the press or rolling mill.

After the rolling or pressing is completed the frame of the bottom half of the matrice is unscrewed, carrier hooks are pushed under the pressed article and the article is removed along a run way to the finishing shop.

In dealing with large work of this nature I have found that the apparatus must be arranged with a view to quickness of operation. The resistances must be readily removable at one and the same time and the sheet made accessible and readily withdrawable for immediate pressing. rolling, or moulding, and the apparatus hereinbefore described possesses these necessary features.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1..A furnace comprising the combination of a ivotally supported casing. having a hinge side and a removable side. resistance members extending from one side to the other side, and conductors connected to the resistance members.

2. A furnace comprising the combination of a pivotally supported casing, having a hinged side and a removable side. resistance members extending from one side to the other side, a longitudinally divided hinged top disposed on the casing, and conductors connected with the resistance members.

3. A furnace comprising the combination of a pivotally supported casing, having a hinged side 'and a removable side, an upper and lower lining disposed in the casing, means for adjusting the upper and lower linings with relation to each other, resistance members extending from one side to the hinged side,

the tracks and adapted to close the adjacent other side of the casing, and conductors connected with the resistance members.

4. A furnace comprising the combination of a pivotally supported casing, having a hinged side and a removable side, and having a sectional hinged top, sectional lining members disposed adjacent the top and bottom of the casing, adjusting members having. their inner ends connected to the sectional lining members and projecting through the top and bottom of the casing, resistance members disposed between the lining members and extending from one side of the casing to the other side, and conductors removably connected to the resist ance members.

5. A furnace comprising the combination of a casing having a top. bottom and a hinged side wall, supporting tracks arranged at the side of the casing opposite its a wheeled closure disposed on side of the casing, resistances secured to the Wheeled closure and removably connected to the opposite side and conductors removably secured to the hinged side and carried by the wheeled closure.

6. A furnace comprising the combination of a casing having a top, a bottom, a hinged side and a removable side, electrodes carried by the hinged side, resistance members carried by the removable side and having their opposite ends disposed in the electrodes, and removable conductors secured to the casing.

7. A furnace comprising the combination of a casing having a top, a bottom, a hinged side and a. removable side, electrodes carried by the hinged side, resistance members carried by the removable side and having their opposite ends disposed in the electrodes. means for clamping the electrodes on the resistance members, and removable conductors secured to the casing.

In witness whereof I have hereto set my v hand in the presence of two witnesses;

PAUL LUDWIG PFANENSCHMIDT.

Witnesses:

CLEVE WAUGH, FRANK FATE. 

